


Sweet Little Pervert

by multibean



Category: Shingeki no Kyojin | Attack on Titan
Genre: Anal Sex, Dom/sub Undertones, I Can't Believe I Wrote This, Loss of Virginity, M/M, Oral Sex, Pain, Shameless Smut, Size Difference, Spanking
Language: English
Status: Completed
Published: 2018-07-28
Updated: 2018-07-28
Packaged: 2019-06-17 15:44:49
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,230
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15464736
Author URL: https://archiveofourown.org/users/multibean/pseuds/multibean
Summary: “This,” Erwin begins, running the cane along the boy’s backside, “this cute little arse here is all mine. Are we clear, Arlert?”The smaller shudders. “Yes, Commander.”“Mmm,” he hums approvingly. “Now... take a deep breath.”





	Sweet Little Pervert

**Author's Note:**

> This is so dirty holy crap

Erwin grips Armin’s collar in one hand and the flat wooden cane in the other. The big, dewy blue eyes follow the object as he slowly waves it before him, teasing. Armin swallows hard, trembling.

The larger man lifts him with ease, settling him onto his lap. Armin suddenly feels so tiny, so lithe. He peers down, noticing that Erwin’s thick, toned thighs are over double the width of his, his pinky finger wider than even his thumb.

“Armin,” he says softly, hands caressing his thighs and waist. “You remember your safeword, I assume?”

Armin nods.

“Good boy,” Erwin whispers, leaning down to kiss the side of his neck. Armin gasps, growing more and more aroused by the second.

He turns him over practically effortlessly and Armin squeals, overcome with adrenaline. He knows it’s going to hurt. It always hurts. But _oh_ , it’s _so_ good, so so good that Armin’s sure that it alone could bring him right up to climax if it went on long enough.

Erwin tugs down his garments, revealing the pert little arse he’s seen so many times now, skin he’s delivered sharp blows to several times before. It’s void of any evidence of their previous encounters. The skin is smooth and pale and perfectly soft as if untouched.

Erwin takes a shuddering breath while he squeezes the fleshy cheeks, and Armin whimpers with anticipation. He attempts to squirm away, but Erwin’s strong, far stronger than he’ll ever be.

“This,” Erwin begins, running the cane along the boy’s backside, “this cute little arse here is all mine. Are we clear, Arlert?”

The smaller shudders. “Yes, Commander.”

“Mmm,” he hums approvingly. “Now... take a deep breath.”

He cracks it down with full force. It’s only the first, but already Armin’s shrieking and writhing and gasping. It stings and aches and burns. And it’s orgasmic.

“ _Ohh!_ ” Armin sobs as Erwin brings it down again, slowly reddening the skin with each hit.

Erwin’s smirking. He feels his cock twitch when Armin gives a particularly low, provocative groan, sounding pained and yet incredibly satisfied all at once.

Ten more, and Armin can hardly breathe. His cock is swollen and throbbing under his clothes, untouched. It never quite feels real when Erwin does these things to him. It all happens so quickly and so slowly all at once.

“Erwin!” he finally cries out after another five or so; he’s lost count and can barely form a coherent sentence. “S-sir! Sir, I-I can’t, I have to, I mean, I want - UNGHHH! - Ow! Ahh... Commander...!”

“Hush,” Erwin tells him gently, all while still bringing down the flat piece of wood. Armin squeals again, still trying to wriggle free, but Erwin lays his hands flat on his back to keep him still.

“Oh,” Armin moans quietly, gradually stilling. “Oh... god... sir, please!”

“What is it?” Erwin asks, not stopping his ruthless blows.

“Please,” Armin barely manages. His voice is broken and pitched and wavers with every hit. “Please, I can’t, I need...”

“What, now?” He pauses and for a moment Armin thinks he’s finished, only for another crimson mark to be made upon his round little backside.

“I need you to make me come,” Armin cries out. “Please, Erwin, you promised, you said y-you’d do it this time, please don’t keep me like this, I can’t stand it it hurts I need to- mmph!” He’s cut off when a hand gently clamps itself over his mouth.

“I know,” Erwin whispers, putting down the cane and smoothing down the skin he’d been reddening just a minute ago. “Alright then, love. Sit up.”

“Ahh...” That’s the thing Armin can’t get enough of, the thing he adores about Erwin: he always knows when he’s had enough, knows how to give him the pain he craves so badly without it being too much. He’ll sit there and punish him and tell him how bad he’s been and spank him until he’s screaming, but then he’ll stop and hold him close and kiss him, tell him how well he’s taken it, how much he loves him. It makes Armin fall in love over and over again, every time.

He gasps when Erwin lifts him, carrying him over to the bed. He glances over to the door on instinct, breathing a sigh of relief when he sees that Erwin’s bolted it shut. He doesn’t want any more awkward encounters.

“What are you...” Armin begins, but all concern leaves his head as soon as he’s pushed onto the mattress, face-down, his trousers yanked from his body to expose his still very tender behind completely. He gasps at how it still tingles.

Erwin is breathing heavily and audibly, and his hot breath grazes over Armin’s skin as he leans down, carefully prying the cheeks apart. Armin adores how he’s always so tender and soft after he’s spanked him, careful not to spark any more pain than he needs.

“You okay, love?”

Armin nods. “Y-yeah...”

“How are you feeling?”

“Aroused.”

“Is that so?”

“Yes, sir. I’m... very turned on. I’d really appreciate if you’d p-pleasure me, please.”

Erwin chuckles happily. “Of course. Good boy.”

He presses his face against Armin’s back, trailing his lips against the soft skin and smiling when Armin shudders. “Ah, Armin,” Erwin begins, starting to pepper him with soaking kisses. “Oh, Cadet Arlert, you’re perfect. So perfect, for me. So pretty. Sweet thing. You deserve the world. You’re gorgeous, Armin.”

“Hahh...” the smaller responds, feeling every ounce of tension leave his body. Erwin’s voice is always so _calm._ It has a harsh, baritone ring to it, and yet it’s oddly soothing, always works on Armin like some kind of sedative.

“Armin.”

He freezes at the sudden sound of his name, Erwin ceasing to deliver his affections and reaching down to squeeze his hands around the sore cheeks instead. He gently pries them apart, and the cool air against his delicate entrance makes Armin shudder.

“Y-Yeah?”

“I’m going to pleasure you,” Erwin says firmly. “I’m... going to bring you ecstasy, if I can.”

“Ah... yeah.” The smaller squeezes his eyes shut, wondering exactly what he’s planning on doing. His heart begins to pound in anticipation, Erwin’s heavy presence behind him setting him on edge. His large build feels incredibly hot, incredibly _alive_.

* * *

Erwin’s tongue is hot, almost too hot for such a delicate, sensitive area. It’s soft and soaking and yet also very slightly rough, the way a cat’s is.

At first, Armin _wails_. He’s never felt so sinful and humiliated, so exposed. Never in his life did he think he’d be in such a position - face pressed down, hair splayed out across the pillow, his hips raised ever so slightly with another man’s tongue lapping at his-

“Mmph!” Armin suddenly whines, voice muffled by the pillow. Erwin simply chuckles. He knows Armin’s embarrassed about enjoying this so much, being tasted in such an intimate area but Erwin’s so skilled and it’s so good and he f... feels s... so... _oh god._

Erwin presses forwards, trying to breach the tight hole. There’s a fair bit of resistance, but once he gets it nice and wet and Armin becomes relaxed enough, he’s able to slip his tongue inside with ease. Armin shudders and flinches at the foreign sensation.

“Ungh... agh,” he chokes out as Erwin wriggles his tongue inside him. It’s so sensitive, especially when he thrusts it deeper, wondering if it’ll be long enough to reach the little spot that’ll drive him crazy.

Erwin reaches down and gently grips the backs of Armin’s thighs as he pleasures him sweetly from behind. His legs are soft, smooth and _so_ warm, quivering and trembling, knees knocking together as he wails and moans. He’s physically incapable of stopping himself from shuddering and jolting occasionally when Erwin runs his tongue particularly deep, squirming inside him. He’s become weak at the knees; it’s almost too much, too powerful.

“Commander,” Armin finally manages to say, hiding his face behind his long fringe. “That’s... oh... oh, it’s just too d-dirty.”

“Too dirty?” Erwin repeats, lips still brushing against the boy’s hole. His breath is unbearably hot against it, and Armin shudders yet again.

“It’s gross if you lick me here, it’s embarrassing, it’s too much and I- _nnngh!_ Oh, ohh, Erwin, p-please!”

 _Such a sweet little pervert,_ Erwin thinks fondly as he slides his tongue deeper, the muscle reaching around for any evidence of the small, walnut-sized gland that he knows will have Armin crying out in pure rapture.

Armin’s so flustered, so embarrassed and dazed and excited, so overwhelmed. He doesn’t even realise that he’s moaning, that he chokes out Erwin’s name as he wriggles the tip of his tongue _right against that sweet spot inside,_ his whole body jerking. Almost absently he realises that he’s going to end up coming at this rate, will have orgasmed long before Erwin’s done with him, leaving him lying here all hypersensitive and limp as the large blonde fucks him into submission.

Erwin suddenly realises this and withdraws his tongue. Armin gives a quiet whimper of surprise.

“Tight,” Erwin remarks, his breath hot and tingling against Armin’s tender hole. “So tight, I can feel it squeezing me.” He playfully smacks a hand against Armin’s backside as he sits up. “Are you sure I’m not hurting you?”

“It doesn’t hurt,” Armin says. “It feels really good. Really, really... _good._ ”

“You want to carry on?”

“Yeah...”

“You sure?” Erwin asks gently, soothingly running a hand across the sore, still-pink arse in front of him. “You seem so nervous, and worried. I was concerned that you weren’t enjoying it.”

“No, no, I am!” Armin quickly reassures him, raising his head. “I love it! I’m just not used to acting so dirtily. It’s not me. I’m not... like that. I’m usually so quiet and innocent and the fact that I’m lying here while you eat me out is...” His face has gone red hot again. “It’s uncharted territory. And... it’s good. I like it. I’m just not used to being pleasured by someone else.”

He turns to look, and Erwin is smiling warmly. He’s still fully clothed, and somehow, this makes Armin even shyer.

“Why am I naked when you aren’t?”

“Don’t you find it arousing?” Erwin teases.

“Don’t answer questions with questions! I asked, why aren’t you naked yet? Come on.” He reaches over and grabs at Erwin’s top, trying to pull it off over his head. Erwin resists, looking smug.

“Ugh,” Armin groans, going for his trousers instead. Erwin sighs and obliges this time, allows him to fumble with the belt loops and zip until he’s knelt behind Armin with his erection tenting his underwear.

“Please, Erwin,” Armin begs.

“My love,” Erwin grins, proceeding to strip, “how am I supposed to say no to a voice like that?”

* * *

Armin stares at the ceiling, doing his best to relax. He has butterflies in his stomach, his chest rising and falling with every heavy breath. He doesn’t understand how on earth it’s going to fit. Erwin had fingered him slowly, starting out with one until Armin could take four with only mild pain, but this was _different_ \- he’d seen the man’s length before, and boy, what a length it was.

It was its thickness that concerned him more than anything. How was this going to work?

Armin glances to his side, wondering what’s taking him so long.

“Can’t get it up?” Armin murmurs.

“No, no, it’s not that, I’m looking for the lubricant. I swear I put it- Ah. Here it is.” He shows the small, thin bottle to Armin, who cranes his neck to look. It’s a thin-looking pretty liquid, golden in colour. He wonders what it’s made of exactly.

Armin sighs and leans back as Erwin climbs back onto the bed, gently prying the young man’s legs apart. He resists a little until Erwin leans down and kisses him kindly, relaxing him.

“You sure you’re okay?”

“I’ll be fine. Just please, please go slow. You’re rather huge down there, and I still don’t understand how this is going to work, but I’ll be fine.”

“You sure you want this, Armin? You’re not going to regret this or anything, are you? I’m not going to be disappointed in you if there’s anything you don’t want to do.”

“I want it,” the smaller blonde says. “I have to lose it at some point, Erwin. It might as well be now while I feel ready. Just please don’t be rough. That’s all I ask. I’ll need time to adjust.”

Erwin nods gently. “I understand,” he says, Armin hoisting himself upwards to rest his legs against each side of Erwin’s waist. Such close skin-to-skin contact feels so _weird,_ so alien somehow despite them having held eachother close like this before. The atmosphere and Armin’s nerves make this feel foreign and odd to him, makes Erwin’s large build seem even more menacing than usual, if that was even possible.

Armin focuses in on the patterns of the ceiling when he feels the blunt head pressing against his entrance, trying not to tense up with anxiety. The pressure quickly becomes painful - it feels so solid and heavy, so thick, so _impossible_ for him to take in.

“Ah, ow!” Armin complains, wriggling away to relieve the pressure. “Ow! Crap!”

“So sorry,” Erwin says hurriedly. “Do you want me to add more lubricant? I’ll admit I wasn’t very generous with it... it’s quite expensive.”

“Yes please,” Armin pants, shuffling back into position.

“I’m ever so sorry, Armin,” Erwin apologises again, his hands soothingly rubbing the inside of the boy’s thighs. “We don’t have to do this, okay? It’s alright. I won’t pressure you, my sweet.”

“I want to, though,” Armin insists.

“Then I’ll try again,” says Erwin, coating himself with the oil and prodding a couple of slippery fingers into Armin, who gasps with surprise. “Let me loosen you up more. You’re tense. Try not to clamp down so much.”

Armin breathes in deeply, holds it for a few seconds, and then when he exhales, he relaxes every muscle in his body.

“Yes. Like that,” the Commander praises, feeling him grow less tense around his fingers. “That’s perfect. See if you can stay relaxed like this.”

Armin stares up again, drawing up his legs. _The more nervous I am, the more painful it’ll be,_ he tells himself, breathing deeply. _Once I’m used to it, I know I’ll love it._

Once again he feels the hardness poking at his hole, pressing, pressing until it gradually manages to breach it. It stings and aches terribly.

“Ah. Ahh. Ouch,” Armin groans, but encourages Erwin to continue when he suddenly stops. Armin grits his teeth, willing the pain away.

And, just as quickly as it had appeared, it subsides.

“Oh,” Armin gasps.

“What is it?”

“It’s... suddenly better,” he replies. “It aches, but most of the pain is suddenly gone. Are you...” He cringes at his awkwardness. “Are you... inside?”

Erwin nods. He thrusts forwards a little more almost as if to prove his point, meeting his hips against Armin’s.

Armin suddenly finds himself revelling at what he’s doing. _I’m actually having sex,_ he realises as Erwin gently pulls out again, and then pushes back in just as gently, the awful stinging returning but only for a second. _I’m finally doing something I never thought I’d be brave enough to do._

“Ahh,” Erwin groans, hands tightening around Armin’s thighs. “You’re extremely tight, Armin. Very, very tight. So nice and hot inside, so good.”

“Mmph,” Armin responds, gasping when Erwin picks up the pace a little. It still aches, but a small part of him suddenly screams out that this is _good_ , that he’s feeling pleasure, that he’s happy.

The voice becomes audible then, erupting from his throat as a loud, obscene moan.

Erwin stills at this before a smile of realisation dawns on his face. “You like it already?” he asks, holding Armin close as he carefully penetrates him again.

“Yes,” Armin pants, splaying himself out and giving a half-sigh, half-moan. It’s at that point that Erwin suddenly rams into him, eliciting a shrill scream from the smaller, who feels his body quiver and tense in a cross between bliss and agony.

“Ah... YES!” Armin yells out, arching his hips involuntarily. “Oh...! My god-“

Erwin chuckles and changes the angle of his thrusts, overwhelmed with excitement when Armin begins to cry out again. What had started with anguish is quickly turning into rapture.

He’s fucking him so good, so accurately, in all the right places.

Erwin watches Armin as he continues his quick, rough pace, amazed at how quickly the young man had managed to adjust to something so huge entering his body. His eyes are pressed shut, head tilted back, gorgeous golden locks spread out beside his head, his lips bitten raw. He’s trying to keep quiet, keeping his lips sealed as he moans and whines, but it’s no use - the sounds flood Erwin’s ears and make his stomach twinge with heat.

“So perfect,” the man utters, still gazing down at Armin’s cute face. “So good, for me. So wonderful. Oh, Armin. So warm and tight, I can... nghh. I can barely... take this, Armin. I’m sorry. I don’t think I’ll last. I have to come in you right now. I have to. It’s too... too good.”

He reaches his climax then, feeling himself tip right over into ecstasy. He’s groaning and hissing, feeling his cock pulse and throb as it empties its seed inside Armin, the hot fluid filling him up.

Armin shudders. It’s warm and wet, and feels incredibly odd, but something about having Erwin come inside him is so hot, just speaks volumes about how much he’s enjoying this sweet little arse of his.

It takes a few pumps of his hand along his own cock, but then Armin’s coming too, gasping and moaning as his seed is expelled onto the man in front of him. He’s lightheaded and shaking all over.

* * *

“How was that?”

Armin suddenly jolts awake. “Eh?”

“How was it? Did it feel good?”

“Oh... oh, yes,” Armin nods, eyes widening. “Did I fall asleep like this? Ah... crap, I need to clean myself.”

“No need,” Erwin tells him. “I wiped you down, it’s fine. You knocked yourself straight out after you came. You were making these gorgeous noises, and when I next looked up, you were fast asleep. It’s funny how some good dick can put you to sleep like that.”

“Don’t talk so filthily,” Armin says. He draws his legs up, trying to preserve what little modesty he has left.

“You can’t exactly say that after I just fucked you to sleep, Armin.”

“Ugh,” the smaller blonde pouts. “Be quiet.”

“Little pervert,” Erwin says, smiling warmly. “Sweet thing.”

“I’m not a pervert!” Armin insists, trying to climb under the covers.

“Are you sure?” Erwin teases, climbing into bed with him and embracing the exhausted young man. “I’d say a cutie like you who lies there moaning like a whore as he’s licked out from behind is a pervert through and through.”

“Stop that talk,” Armin says, quickly turning around in the hopes that Erwin won’t catch him smiling.

When he’s finally taken by sleep, held safe and warm in the strong arms, Erwin leans over to catch a glimpse of the grin decorating the boy’s face.

 _Such a sweet little pervert_ , Erwin thinks amusedly.

**Author's Note:**

> Forgive me father for I have sinned


End file.
